Organic Chemistry

Substituted benzenes As we can see, the variety of substituents that can be introduced directly on the aromatic ring is not very wide. However, it is possible to transform them into a wide variety of other functions by means of relatively simple reactions, for example: Halogenation of alkylbenzenes at the benzyl position Benzyl hydrogens have … Read more

Special reactions of terminal alkynes Reactions with strong bases Terminal alkynes treated with strong bases such as sodium amidide in liquid ammonia form relatively stable anions. Such anions are nucleophiles that can be used in substitution reactions. One of the possible applications is its use on primary or secondary alkyl halides for the preparation of … Read more

Conversion of alkenes to alkanes Catalytic hydrogenation The addition of one mole of H2 to a double bond leads to the formation of a saturated compound (alkane). The conditions (temperature, pressure, etc.) of hydrogenation are relatively mild, the presence of a catalyst being essential, since the mixture of hydrogen and alkene does not react spontaneously … Read more

Haloalkanes or alkyl halides are compounds derived from alkanes (CnHn) that have one or more halogen functional groups (F, Cl, Br, I) in the carbon chain. The most characteristic reactions are listed below. Reduction to alkanes Reaction of alkyl halides with Zno in an acid medium Treatment with metallic Zn with an aqueous acid of … Read more

Gabriel synthesis Synthetic procedures to obtain amines, such as the reduction of nitro, azido and cyano groups or SN2 reactions in which an amine acted as a nucleophile, have been described in other sections. Gabriel synthesis is a method of obtaining amines, mainly primary, in two steps, starting from alkyl halides and using potassium phthalimide, … Read more

Aromatic hydrocarbons Although formally the structure of benzene would be that corresponding to 1,3,5-cyclohexatriene (i.e. corresponding to a conjugated polyene) its properties do not correspond to those of a polyene. For example, it does not undergo addition reactions under any of the conditions specified in alkene and diene reactions, its heat of hydrogenation is abnormally … Read more

What are dienes? Dienes are compounds that have two double bonds (>C=C<). Depending on the relative arrangement of these double bonds, they have different characteristics. Thus we can have: Isolated dienes The two double bonds are separated by at least one carbon atom. They behave like conventional alkenes, so their reactivity is similar to that … Read more

Radical halogenation The halogenation of alkanes consists of the substitution of one or more hydrogens of a saturated hydrocarbon by a halogen atom or atoms. It is a radical reaction with homolytic halogen cleavage initiated by appropriate radiation (hν) or by the presence of radical initiators (e.g. -O-O- peroxides). Only chlorination and bromination are of … Read more

The most significant reactions in organic chemistry of the functional groups alcohols, ethers and oxiranes are described below. Dehydration of alcohols Alcohols in the presence of mineral acids suh as H2SO4 o H3PO4 they give alkenes by loss of a water molecule. The order of reactivity of alcohol is: tertiary (3º) > secondary (2º) > … Read more

Preparation of derivatives When the OH in a carboxylic acid is replaced by another function such as X (Cl, Br), OR, NH2, etc., compounds called “carboxylic acid derivatives” are obtained. All of them have in common the acyl group (R-C=O). These derivatives are, in turn, converted to acids by hydrolysis, and also give rise to … Read more